Chromatography columns may be used in industrial processes to purify process liquids and separate substances of interested from process liquids. Prior art chromatography columns comprise a column wall in the form of hollow column tube which is connected to a removable upper end plate assembly and a removable lower end plate assembly. One end plate assembly is provided with a process fluid inlet arrangement, typically comprising an inlet pipe and an inlet valve and the other end plate assembly is provided with a process fluid outlet arrangement, typically comprising an outlet pipe and an outlet valve. Each end of the column tube is usually provided in the interior of the column with a removable distributor plate. These inlet and outlet distributor plates may be attached to the respective end plate assembly or the upper distributor plate may be arranged to be movable towards or away from the end plate assembly. During use, the space in the column between the distributor plates is usually filled with a chromatography medium. A retaining mesh is normally provided between each distribution system and the media in order to prevent media particles from escaping the column. The inlet distributor plate is intended to distribute incoming fluid evenly over the surface of the media at the inlet end of the column while the outlet distributor plate is intended to collect fluid evenly from the surface of the media at the outlet end of the column Such a column may weigh several tons.
The retaining meshes extend across substantially the whole internal diameter of the column and are normally fixed along the outer perimeter of the column and at the center of the column. The meshes can be prepared from woven threads of either metals or polymers or they can be made from sintered particles. They can also be multilayer constructions of e.g. several woven meshes joined by sintering. During maintenance of the column it is desirable that the retaining mesh can be easily exchanged for a new one with an arrangement providing good sealing and no stagnant zones that may impair sanitation of the column EP008921(A1) describes a structure with snap ring action for fixing a polyethylene sinter mesh but this solution does not satisfy current needs for sealing and sanitation. There is thus a need for further improvements in this regard.